Transmissions, such as vehicle transmissions, have one or more gear meshes that selectively transfer torque from an input shaft to an output shaft of the transmission. The gear meshes commonly require lubrication during transmission operation. The gear meshes and lubricant may be contained within a transmission case or housing, and an internal sump may be provided to collect drained fluid and act as a reservoir.
Lubrication distribution systems are used to circulate lubricant and provide a sufficient quantity of lubricant to the moving parts of the transmission. Several types of lubrication systems are used. For example, a system referred to as a splash system utilizes a splasher or dipper affixed to one or more of the moving traction parts within an internal cavity of the transmission case. The moving parts are cycled through lubricant within the sump during the movement of parts and lubricant is splashed about the internal cavity of the case. The splash may be diverted using internal features of the transmission such as veins or funnels that direct the flow of lubricant as it drains. Splash systems include a high volume of lubricant and may allow lubricant to slosh within the internal cavity. One problem with splash lubrication is that it is speed dependent. There can be centrifugal effects, hydrodynamic effects, and effects from the gears working as pumps that may reduce efficiency of the transmission.
Dry lubrication systems distribute lubricant differently compared to splash systems. In dry lubrication systems, a significantly smaller volume of lubricant is contained in a sump within the transmission. The lubricant is drawn out of the sump and diverted to the traction components as required. An arrangement of tubes may be used to diverting lubricant to specific locations within the transmission. The arrangement may be complex, and the tubes may be steel tubes that are formed, then brazed or welded to separate nozzles. With metal tube structures, implementing a large number of nozzles presents design and manufacturing challenges. The metal tubes may require unique custom shapes to deliver lubricant to desired locations. The assembly of a large number of customized parts is often expensive and may require complex tooling.
This disclosure is directed to solving the above problem and other problems as summarized below.